Preworkout

Betaine Anhydrous (TMG)

Effective dose
2.5–6 g
Evidence
3/5· Moderate

Last updated June 1, 2026

What it is

Betaine anhydrous, also called trimethylglycine (TMG), is a compound found in beets and other foods that acts as an osmolyte and methyl donor. By supporting cellular hydration and methylation reactions, it is theorized to aid power output and body composition during training.

Benefits

A common dose of 2.5 g daily has been linked to improved body composition and some gains in strength and power output, though results across trials are mixed. Many studies show body-composition changes without clear strength benefits.

When to take it

Take daily, often split into two doses; total daily intake matters more than precise pre-workout timing.

Side effects

Generally well tolerated under 6 g per day; higher intakes may cause gastrointestinal upset or a fishy body odor. May modestly affect blood lipids in some people.

Sources

Products containing Betaine Anhydrous (TMG)

No products in our database contain this ingredient yet.